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A novel graph oversampling framework for node classification in class-imbalanced graphs

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Science China(Information Sciences) 2024年第6期67卷 214-229页

作者： Riting xia Chunxu ZHANG Yan ZHANG Xueyan liu Bo yang Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education Jilin University College of Artificial Intelligence Jilin University College of Computer Science and Technology Jilin University College of Communication Engineering Jilin University

Graph neural network(GNN) is a promising method to analyze graphs. Most existing GNNs adopt the class-balanced assumption, which cannot deal with class-imbalanced graphs well. The oversampling technique is effective in alleviating class-imbalanced problems. However, most graph oversampling methods generate synthetic minority nodes and their edges after applying GNNs. They ignore the problem that the representations of the original and synthetic minority nodes are dominated by majority nodes caused by aggregating neighbor information through GNN before oversampling. In this paper, we propose a novel graph oversampling framework, termed distribution alignment-based oversampling for node classification in classimbalanced graphs(named Graph-DAO). Our framework generates synthetic minority nodes before GNN to avoid the dominance of majority nodes caused by message passing in GNNs. Additionally, we introduce a distribution alignment method based on the sum-product network to learn more information about minority nodes. To our best knowledge, it is the first to use the sum-product network to solve the class-imbalanced problem in node classification. A large number of experiments on four real datasets show that our method achieves the optimal results on the node classification task for class-imbalanced graphs.

关键词： graph neural network class-imbalanced graphs sum-product network oversampling node classification

Analytical methodologies for sensing catechol-O-methyltransferase activity and their applications

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Journal of Pharmaceutical Analysis 2021年第1期11卷 15-27页

作者： Fang-Yuan Wang Ping Wang Dong-Fang Zhao Frank J.Gonzalez Yu-Fan Fan yang-liu xia Guang-Bo Ge Ling yang Institute of Interdisciplinary Integrative Medicine Research Shanghai University of Traditional Chinese MedicineShanghai201203China School of Life Science and Medicine Dalian University of TechnologyPanjin124221China Laboratory of Metabolism Center for Cancer ResearchNational Cancer InstituteNational Institutes of HealthBethesdaMDUSA

Mammalian catechol-O-methyltransferases(COMT)are an important class of conjugative enzymes,which play a key role in the metabolism and inactivation of catechol neurotransmitters,catechol estrogens and a wide range of endobiotics and xenobiotics that bear the catechol ***,COMT inhibitors are used in combination with levodopa for the treatment of Parkinson’s disease in clinical *** crucial role of COMT in human health has raised great interest in the development of more practical assays for highly selective and sensitive detection of COMT activity in real samples,as well as for rapid screening and characterization of COMT inhibitors as drug *** review summarizes recent advances in analytical methodologies for sensing COMT activity and their *** lists of biochemical assays for measuring COMT activity,including the probe substrates,along with their analytical conditions and kinetic parameters,are ***,the challenges and future perspectives in the field,such as visualization of COMT activity in vivo and in situ,are ***,this review article overviews the practical assays for measuring COMT activities in complex biological samples,which will strongly facilitate the investigations on the relevance of COMT to human diseases and promote the discovery of COMT inhibitors via high-throughput screening.

关键词： Catechol-O-Methyltransferase(COMT) Enzymatic activity Probe substrate COMT inhibitor High-throughput screening

Ionic liquid modified GC electrode for the direct electrochemistry of chloroperoxidase

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Chinese Chemical Letters 2008年第12期19卷 1483-1486页

作者： liu yang xia Qin Wu Rong Wang Zhong Qing Lu Wen Jing Hou He Xing Li Life and Environment Science College Shanghai Normal University 100 Guilin Road Shanghai 200234 PR China

Chloropcroxidase （CPO） was immobilized by konjac glucomannan （KGM） on the 1-butyl-3-methyl imidazolium tetrafluoroborate [BMIM][BF4]/Nafion modified glassy carbon eloctrode. The electrochemical behaviors of the immobilized CPO were investigated by cyclic voltammetry. The results showed that CPO was successfully immobilized on the GCE and underwent fast direct electron transfer reactions with the formal potential at -0.3 V vs. SCE. The modified electrode showed a good catalytic activity for elcctrocatalytical reduction of O2 and H2O2.

关键词： Ionic liquid Chloroperoxidase Electroeatalysis Direct electrochemistry

Excess pore pressure behavior and evolution in deep coalbed methane reservoirs

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International Journal of Mining Science and Technology 2024年第6期34卷 763-781页

作者： Changqing liu Zhaobiao yang Yong Qin xia Yan Yunhai Wang Zhe Wang Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process Ministry of EducationChina University of Mining and TechnologyXuzhou 221008China School of Resources and Geosciences China University of Mining and TechnologyXuzhou 221116China National Engineering Research Center of Coalbed Methane Development&Utilization Beijing 100095China PetroChina Coalbed Methane Company Limited Beijing 102200China SINOPEC East China Oil and Gas Company Nanjing 210000China

Deep coalbed methane(DCBM),an unconventional gas reservoir,has undergone significant advancements in recent years,sparking a growing interest in assessing pore pressure dynamics within these *** some production data analysis techniques have been adapted from conventional oil and gas wells,there remains a gap in the understanding of pore pressure generation and evolution,particularly in wells subjected to large-scale hydraulic *** address this gap,a novel technique called excess pore pressure analysis(EPPA)has been introduced to the coal seam gas industry for the first time to our knowledge,which employs dual-phase flow principles based on consolidation *** technique focuses on the generation and dissipation for excess pore-water pressure(EPWP)and excess pore-gas pressure(EPGP)in stimulated deep coal *** have been developed respectively and numerical solutions have been provided using the finite element method(FEM).Application of this model to a representative field example reveals that excess pore pressure arises from rapid loading,with overburden weight transferred under undrained condition due to intense hydraulic fracturing,which significantly redistributes the weight-bearing role from the solid coal structure to the injected fluid and liberated gas within artificial pores over a brief ***,field application indicates that the dissipation of EPWP and EPGP can be actually considered as the process of well production,where methane and water are extracted from deep coalbed methane wells,leading to consolidation for the artificial ***,history matching results demonstrate that the excess-pressure model established in this study provides a better explanation for the declining trends observed in both gas and water production curves,compared to conventional practices in coalbed methane reservoir engineering and petroleum *** research not only enhances the understanding of DCBM re

关键词： Deep coalbed methane Consolidation Excess pore-water pressure Excess pore-gas pressure Production data analysis

Investigation of Projectile Impact Behaviors of Graphene Aerogel Using Molecular Dynamics Simulations

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3047-3061页

作者： Xinyu Zhang Wenjie xia yang Wang Liang Wang xiaofeng liu Department of Engineering Mechanics Shanghai Jiao Tong UniversityShanghai200240China Department of Aerospace Engineering Iowa State UniversityAmesIA50011USA School of Materials Science and Engineering University of Science&Technology BeijingBeijing100083China Zernike Institute for Advanced Materials University of GroningenGroningen9747The Netherlands

Graphene aerogel(GA),as a novel solid material,has shown great potential in engineering applications due to its unique mechanical *** this study,the mechanical performance of GA under high-velocity projectile impacts is thoroughly investigated using full-atomic molecular dynamics(MD)*** study results show that the porous structure and density are key factors determining the mechanical response of GA under impact ***,the impact-induced penetration of the projectile leads to the collapse of the pore structure,causing stretching and subsequent rupture of covalent bonds in graphene ***,the effects of temperature on the mechanical performance of GA have been proven to be minimal,thereby highlighting the mechanical stability of GA over a wide range of ***,the energy absorption density(EAD)and energy absorption efficiency(EAE)metrics are adopted to assess the energy absorption capacity of GA during projectile *** research findings of this work demonstrate the significant potential of GA for energy absorption applications.

关键词： Graphene aerogel molecular dynamics simulation impact response energy absorption

Unlocking the potential of amorphous calcium carbonate: A star ascending in the realm of biomedical application

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Acta Pharmaceutica Sinica B 2024年第2期14卷 602-622页

作者： Han liu Zhiyang Wen Zihan liu Yanfang yang Hongliang Wang Xuejun xia Jun Ye Yuling liu State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China Beijing Key Laboratory of Drug Delivery Technology and Novel Formulation Institute of Materia MedicaChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China

Calcium-based biomaterials have been intensively studied in the field of drug delivery owing to their excellent biocompatibility and ***-based materials can also deliver contrast agents,which can enhance real-time imaging and exert a Ca^(2+)-interfering therapeutic *** on these characteristics,amorphous calcium carbonate(ACC),as a brunch of calcium-based biomaterials,has the potential to become a widely used *** functional ACC can be either discovered in natural organisms or obtained by chemical synthesis However,the standalone presence of ACC is unstable in *** are required to be used as stabilizers or core-shell structures formed by permeable layers or lipids with modified molecules constructed to maintain the stability of ACC until the ACC carrier reaches its *** has high chemical instability and can produce biocompatible products when exposed to an acidic condition in vivo,such as Ca^(2+) with an immune-regulating ability and CO_(2) with an imaging-enhancing *** to these characteristics,ACC has been studied for selfsacrificing templates of carrier construction,targeted delivery of oncology drugs,immunomodulation,tumor imaging,tissue engineering,and calcium *** in this paper has been placed on the origin,structural features,and multiple applications of ***,ACC faces many challenges in clinical translation,and long-term basic research is required to overcome these *** hope that this study will contribute to future innovative research on ACC.

关键词： Amorphous calcium carbonate Drugdelivery system Nanoparticle Acid sensitivity Water instability,Tumortherapy Tissue engineering Calcium supplement

A Neural-network-based Alternative Scheme to Include Nonhydrostatic Processes in an Atmospheric Dynamical Core

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Advances in Atmospheric Sciences 2024年第6期41卷 1083-1099,I0002,I0003页

作者： yang xia Bin WANG Lijuan LI Li liu Jianghao LI Li DONG Shiming XU Yiyuan LI Wenwen xia Wenyu HUANG Juanjuan liu Yong WANG Hongbo liu Ye PU Yujun HE Kun xia Ministry of Education Key Laboratory for Earth System Modeling and Department of Earth System ScienceTsinghua UniversityBeijing 100084China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Innovation Group 311020008 Southern Marine Science and Engineering Guangdong LaboratoryZhuhai 519000China Shanghai Ecological Forecasting and Remote Sensing Center Shanghai 200030China Key Laboratory of Earth System Modeling and Prediction China Meteorological AdministrationBeijing 100081China College of Ocean Sciences University of Chinese Academy of SciencesBeijing 100049China

Here,a nonhydrostatic alternative scheme(NAS)is proposed for the grey zone where the nonhydrostatic impact on the atmosphere is evident but not large enough to justify the necessity to include an implicit nonhydrostatic solver in an atmospheric dynamical *** NAS is designed to replace this solver,which can be incorporated into any hydrostatic models so that existing well-developed hydrostatic models can effectively serve for a longer *** advances in machine learning(ML)provide a potential tool for capturing the main complicated nonlinear-nonhydrostatic *** this study,an ML approach called a neural network(NN)was adopted to select leading input features and develop the *** NNs were trained and evaluated with 12-day simulation results of dry baroclinic-wave tests by the Weather Research and Forecasting(WRF)*** forward time difference of the nonhydrostatic tendency was used as the target variable,and the five selected features were the nonhydrostatic tendency at the last time step,and four hydrostatic variables at the current step including geopotential height,pressure in two different forms,and potential temperature,***,a practical NAS was developed with these features and trained layer by layer at a 20-km horizontal resolution,which can accurately reproduce the temporal variation and vertical distribution of the nonhydrostatic *** by the NN-based NAS,the improved hydrostatic solver at different horizontal resolutions can run stably for at least one month and effectively reduce most of the nonhydrostatic errors in terms of system bias,anomaly root-mean-square error,and the error of the wave spatial pattern,which proves the feasibility and superiority of this scheme.

关键词： neural network nonhydrostatic alternative scheme atmospheric model dynamical core

Modeling Near-Field Impulsive Waves Generated by Deformable Landslide Using the HBP Model Based on the SPH Method

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Journal of Ocean University of China 2024年第2期23卷 328-344页

作者： WANG Wei WEI Weicheng CHAI Bo xia Hao WANG yang DU Juan liu Jizhixian School of Environmental Studies China University of GeosciencesWuhan 430078China Hubei Key Laboratory of yangtze Catchment Environmental Aquatic Science Wuhan 430078China Faculty of Engineering China University of GeosciencesWuhan 430074China Research Center for Geohazards Monitoring and Warning in Three Gorges Reservoir Wanzhou 404000China

Landslide-generated impulsive waves(LGWs)in reservoir areas can seriously threaten waterway safety as well as hu-man life and properties around the two side *** risk reduction and mitigation of such a hazard require the accurate prediction of near-field wave characteristics,such as wave amplitude and ***,near-field LGW involves complicated fluid-solid ***,the wave characteristics are closely related to various aspects,including the geometry and physical features of the slide,river,and body of ***,the empirical or analytical methods used for rough estimation cannot derive accurate results,especially for deformable landslides,due to their significant geometry changes during the sliding *** this study,the near-field waves generated by deformable landslides were simulated by smoothed particle hydrodynamics(SPH)based on multi-phase *** deformable landslides were generalized as a kind of viscous flow by adopting the Herschel-Bulkley-Papanastasiou(HBP)-based nonNewtonian rheology *** HBP model is capable of producing deformable landslide dynamics even though the high-speed sliding process is *** this study,an idealized experiment case originating from Lituya LGW and a practical case of Gongjiafang LGW were reproduced for verification and *** simulation results of both cases show satisfactory consistency with the experiment/investigation data in terms of landslide movement and near-field impulsive wave characteristics,thus indicating the applicability and accuracy of the proposed ***,the effects of the HBP model’s rheological parameters on the landslide dynamics and near-field wave characteristics are discussed,providing a parameter calibration method along with sug-gestions for further applications.

关键词： deformable landslide impulsive waves near-field SPH nonNewtonian fluids

Phenylhydrazone anions excitation for the photochemical carbonylation of aryl iodides with aldehydes

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Chinese Chemical Letters 2024年第4期35卷 346-351页

作者： Lei Shen yang Zhang Linlin Zhang Chuanwang liu Zhixian Ma Kangjiang Liang Chengfeng xia Key Laboratory of Medicinal Chemistry for Natural Resource Ministry of EducationYunnan Provincial Center for Research&Development of Natural ProductsSchool of PharmacyYunnan UniversityKunming 650500China

Spectroscopic investigations discovered that the in-situ generated phenylhydrazone anion was significantly bathochromically shifted to visible light region for photoactivation under irradiation. The photoexcited phenylhydrazone anion was potential to reduce aryl iodides via single electron transfer process for the subsequent radical chain reaction. A redox-neutral photochemical carbonylation of aryl iodides was developed on basis of the special spectroscopic features of phenylhydrazone anion. This protocol provided a convenient and efficient synthetic tool for accessing carbonylation products under redox neutral conditions without the need of transition-metals.

关键词： Organic anion Hydrazone Carbonylation Visible light Single electron transfer